package com.rico.gateway.utils;


import lombok.extern.slf4j.Slf4j;
import org.springframework.http.HttpHeaders;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.util.StringUtils;

/**
 * 获取本地IP地址等信息(部署到docker下也OK)
 *
 * @author xieyuanqing
 */
@Slf4j
public class IPAddressUtils {

    /**
     * 获取用户真实IP地址，不使用request.getRemoteAddr();的原因是有可能用户使用了代理软件方式避免真实IP地址,
     * <p>
     * 可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值，究竟哪个才是真正的用户端的真实IP呢？
     * 答案是取X-Forwarded-For中第一个非unknown的有效IP字符串。
     * <p>
     * 如：X-Forwarded-For：192.168.1.110, 192.168.1.120, 192.168.1.130
     * <p>
     * 用户真实IP为： 192.168.1.110
     *
     * @param request
     * @return
     */
    public static String getIpAddress(ServerHttpRequest request) {
        HttpHeaders headers = request.getHeaders();
        String ip = headers.getFirst("x-forwarded-for");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = headers.getFirst("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = headers.getFirst("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = headers.getFirst("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = headers.getFirst("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddress().getAddress().getHostAddress();
        }
        if (StringUtils.hasText(ip)) {
            ip = ip.split(",")[0];
            // 0:0:0:0:0:0:0:1 是ipv6的回环地址，和Ipv4的127.0.0.1是相等的
            if ("0:0:0:0:0:0:0:1".equals(ip)) {
                ip = "127.0.0.1";
            }
            return ip;
        } else {
            return "";
        }
    }


}
